Technical Field
The present disclosure relates to surgical stapling instruments for applying surgical fasteners or staples to body tissue and, more particularly to surgical stapling instruments utilizing bent backspan staples and having a corresponding anvil including bent staple forming buckets.
Description of Related Art
Surgical stapling devices for applying an annular array of staples or fasteners to tissue are well known in the art. For example, such surgical stapling devices have particular utility in performing small bowl resection with end-to-end anastomosis. These devices, typically, include a staple pusher assembly or member and an anvil assembly or member at the distal end of the surgical stapling device. The anvil member is movable from a retracted configuration for positioning tissue between the anvil member and the cartridge assembly, to an advanced configuration for joining tissue, i.e., stapling the ends of a tubular organ in a body of the patient organ to be joined. One or more annular or circular arrays of fasteners, such as, for example, staples, is operably housed in the cartridge assembly. The anvil member includes one or more corresponding annular arrays of staple forming bucket members that clinch or form (e.g., in a “B” staple formation) the staples after the staples are expelled from the cartridge assembly. Generally, the staples include a straight backspan. As can be appreciated, the anvil bucket members and/or pushers associated with the cartridge assembly include a corresponding configuration, i.e., a generally straight configuration, to accommodate the straight backspan of the staples.
For a given staple pusher configuration configured for use with straight backspan staples, the number of staples that may be present in a given annular array of staples is limited by the length of the backspan of the staples and an inside and outside diameter of the cartridge assembly. Moreover, it is, typically, an inside annular array of the staples that determine the number of staples that may be present in each additional annular array of staples, e.g., middle and outer annular arrays, of the cartridge assembly. That is, an equal number of staples in each of the annular arrays is, typically, provided to allow for consistent overlap at a gap between each consecutive staple; a specific gap distance exists between each consecutive staple for each annular array of staples, with, typically, the smallest gap distance between each consecutive staple existing in the inner annular array and the gap distance between consecutive staples increasing from the inner annular array to the outer annular array(s). As a result thereof, the gap distances between consecutive staples in the inner and subsequent annular array(s) are unequal. These unequal gap distances are not conducive to obtaining a “tight” staple line. That is, an equal gap distance between consecutive staples in each annular array of staples may promote better healing of the stapled tissue, which, in turn, results in less bleeding and leakage at the stapled tissue line. Unfortunately, the length of the backspan of the aforementioned staples is limited by geometry from interfering with, i.e., extending into, the next row of staples. As a result thereof, subsequent to tissue being stapled with conventional surgical stapling devices, there exists a chance of bleeding and leakage occurring at the stapled tissue line, i.e., adjacent the area between consecutive staples in the annular array of staples in the outer annular array(s). Or, in certain instance, a compromised stapled tissue line being formed, which, in turn, may result in the stapled tissue separating.